(CNN) - Former Sen. Fred Thompson of Tennessee jumped into the immigration showdown with former New York Mayor Rudy Giuliani and former Massachusetts Gov. Mitt Romney, saying that although immigrants are part of what makes the United States a great nation, "It's our home. We now get to decide who comes into our home. To place somebody above [those waiting for legal immigration] or in front of them in line is the wrong thing to do."

Thompson said federal funding should be cut off to cities that provide sanctuary to illegal immigrants.

Thompson also took a jab at Giuliani, who bashed Romney for employing illegal immigrants, and defended his own record of employee scandals.

"I think we've all had people probably that we've hired that in retrospect probably was a bad decision," Thompson said, referring to a campaign fundraiser and personal friend who resigned from the Thompson campaign because of drug-related crimes and issues with the IRS.